Numerous jewels today are enhanced or treated to unleash their inherent beauty and improve their overall look.
Gemstone treatment refers to any process, other than cutting and polishing, that improves or alters the appearance (colour, clarity, or phenomena) of a gemstone.
Here are some of the most popular treatments used to enhance a jewel’s appeal.
- Heat Treatment
- Irradiation Treatment
- Fracture or Cavity Filling Treatment
- Beryllium Treatment
- Diffusion Treatment
- Bleaching
1. Heat Treatment
Heat treatment is, perhaps, the oldest and most common technique used on gems. As the name suggests, the stones are exposed to high temperatures to alter their colour (make it lighter or darker), and also minimize the appearance of inclusions. However, subjecting them to intense heat can make them more brittle than usual, and therefore such stones require more care and maintenance.
Commonly Used On: In most cases, the desirable hues of gems like, the sapphire, tanzanite, citrine and pink topaz, among others, are all a result of this particular type of enhancement. While rubies, aquamarines, and sapphires are typically heat-treated to deepen their colour, amethyst and tourmaline undergo this process to lighten their hue.
2. Irradiation Treatment
In this treatment, gemstones are bombarded with subatomic particles or radiation to change their colour permanently. In some cases, irradiation is followed by heating to further intensify the gem’s hue, leading to what is known as a ‘combination treatment’.
Commonly Used On: This treatment is frequently used for giving colourless topaz their distinct blue hue. Some other jewels that may undergo this particular type of enhancement include sapphires, quartz, and coloured diamonds.
3. Fracture or Cavity Filling Treatment
This treatment focuses on filling the surface-breaking fractures or cavities present on gemstones. The material used for the process usually includes colourless glass, resin, oil or wax. These items also help increase the clarity and durability of the stone. Since the results of this enhancement are not permanent, interaction with high heat and household cleaners, along with changes in air pressure can cause the gemstones to lose-out the fillers.
Commonly Used On: Diamonds, rubies, emeralds, and sapphires are some popular gemstones that may be subjected to this treatment.
4. Beryllium Treatment
In comparison to other treatments, this method is the most recent technique of treating gemstones. It uses an element known as beryllium, which penetrates deep into the gem during the heating process and is responsible for giving the jewel a rich and intense tone.
Commonly Used On: Although this is mostly used for treating pink, yellow, and orange sapphires, it can be used on rubies as well.
5. Diffusion Treatment
Diffusion treatment involves heating gems at extremely high temperatures and adding elements such as beryllium, chromium, and/or titanium to the process before they can crystallize. This treatment is done to permanently enhance the colour of the jewel, however, it is not always the most stable, and can fade with time.
Commonly Used On: This is often used to give corundum (rubies and sapphires) a desirable hue.
6. Bleaching
In this particular process, a chemical is used to change the colour of the stone. Sometimes, after bleaching, the gem is dyed to completely change its hue.
After this process, the stone may also require an impregnation treatment to fill up the surface cracks (usually done using wax or polymer) and improve its resistance to breakage. Overall, gemstones that are subjected to these treatments require a lot of care. Also, over-exposure to harsh light or heat must be avoided as that can lead to damage.
Commonly Used On: This treatment is often carried out on porous jewels, like the pearl.
As evident from above, some treatments are permanent while some are not. So it’s advisable to take precautions when handling certain gemstones that you know for sure are enhanced.
As a rule of thumb, avoid prolonged exposure to sunlight and protect your gemstones from harsh chemicals to retain their beauty for years to come.
Also Read: How to Store Gemstone Jewellery?
